The invention relates to a system of lamellas for ventilation devices to control the flow of air, particularly for ventilating motor vehicles, with several lamellas, the movement of which is coupled and which can be moved by actuating a preferably manual adjusting element for opening and closing an air duct, the lamellas being in operative connection with the adjusting element by way of a cog, which engages a guiding groove that can be moved by actuating the adjusting element.
Such systems of lamellas are known in the art and find use preferably in motor vehicles in the area of the dashboard. With them, it is possible to regulate the ventilation of the interior of the vehicle individually by opening and closing the lamellas, it being possible to move the lamellas between a closed, first end position and an open, second end position. Starting from the closed position, the lamellas are swiveled open continuously until they reach the completely open position, it being possible occasionally to swivel the lamellas further to guide the air stream in a different direction. In the case of known systems, the lamellas can be swiveled in such a manner, that a laterally protruding cog, which engages a guiding groove that can be actuated by the adjusting element, is provided at a bracket coupling the movement of the lamellas. The guiding groove is moved by means of the adjusting element. This causes the cog to travel in the guiding groove. If the guiding groove is shaped appropriately, the bracket, coupling the motion and, with that, the lamellas, are moved. In the state of the art, a manually actuated rotating wheel, which can be rotated between two end positions, which define the respective end positions of the lamellas, is usually used by the driver or passenger as adjusting element. In the case of a known system of lamellas, as used, for example in the "Passat" series of Volkswagen vehicles or the 7 series of BMW vehicles, a sun-and-planet gear is disposed on the inside of the rotating wheel, the sun-and-planet gear interacting with a disk, which is also fixed to the rotating wheel and has a guiding groove. If the rotating wheel is now moved, the rotational movement is transferred over a first ring gear, fixed to the rotating wheel, to a positionally stationary gear wheel, which in turn meshes with an internal ring gear of said disk having the guiding groove. In this way, the rotary movement of the rotating gear is transferred to the guiding groove. It is an obvious disadvantage of this known system that, for transferring the rotational movement, an extremely complicated sun-and-planet gear is required. which consists of the two ring gears of the rotating wheel and of the disk with the groove, as well as of the coupling planet wheel. That this results in installation difficulties is obvious. Furthermore, the number of parts required is appreciable. A further striking disadvantage consists therein that, for swiveling the lamellas completely from the closed first end position to the open second end position, it is necessary to rotate the rotating wheel several times over that part of its surface, which can be taken hold of by the actuator; this means that it must be grasped repeatedly in order to carry out the complete movement. This is the result of the quasi indirect coupling by means of the sun-and-planet gear and is disadvantageous for the actuator especially while driving, since the driver must concentrate on this.